Mode Of Mechanical Ventilator

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Mode Of Mechanical Ventilator

  1. 1. Mode of Mechanical Ventilator 柳營奇美醫院呼吸治療科 呼吸治療組長 龔淑貞
  2. 2. 模式 (Mode) <ul><li>模式的定義─ </li></ul><ul><ul><li>病人與呼吸器交互作用,以完成一個呼吸器循環 (ventilator cycle) 的方法 </li></ul></ul><ul><ul><li>並沒有任何一種呼吸器模式是最好的 </li></ul></ul><ul><ul><li>醫護人員的經驗與技巧 才是決定一個呼吸器模式成功與否最重要的關鍵 </li></ul></ul>
  3. 3. Mode of MV <ul><li>Conventional methods of ventilator support </li></ul><ul><li>--CMV, A/C, PCV, VCV, IMV, SIMV, PSV </li></ul><ul><li>Alternative methods of ventilator support </li></ul><ul><li>--IRV, MMV, APRV, Bi-phasic, Servo-controlled pressure(Paug, VAPS, PRVC, Auto-flow, APV) , PAV, ATC, ASV </li></ul>
  4. 4. <ul><li>Control mechanical ventilation(CMV) </li></ul><ul><li>-- time trigger, volume or pressure , no effort at Pt. </li></ul><ul><li>Assist-control Ventilation( A/C) </li></ul><ul><li>-- Time or Pt trigger </li></ul><ul><li>-- Set: f, Sensitivity., type of breath(V or P) </li></ul><ul><li>(1) flow controlled, volume cycled (VV): </li></ul><ul><li>flow, volume preset, Vt reach ->flow ends </li></ul><ul><li>(2) pressure controlled, time cycled (PV): </li></ul><ul><li>pressure,Ti preset, Ti reach ->cycle off </li></ul>
  5. 5. Assisted vs. Controlled Time (sec) Assisted Controlled Pressure (cmH 2 0)
  6. 6. Volume Ventilation(VV) <ul><li>Set the volume delivered during the mandatory breath </li></ul><ul><li>VV guarantees volume (C,R ↑↓->V 不變 ) </li></ul><ul><li>Lung worsens, ↑peak and alveolar P. ->overdistention ->change flow pattern 改善 </li></ul><ul><li>High volume give high peak and plateau P. </li></ul><ul><li>Set parameter(7200 ; 900) </li></ul><ul><li>Flow controlled, Time or Pt trigger, volume limit, Volume cycle </li></ul>
  7. 7. Controlled Mode (Volume-Targeted Ventilation) Preset V T Volume Cycling Dependent on C L & R aw Time (sec) Flow (L/m) Pressure (cm H 2 O) Volume (mL) Time triggered, Flow limited, Volume cycled Ventilation Preset Peak Flow
  8. 8. Pressure Ventilation (PV) <ul><li>Preset a pressure, P. limit ventilation (PCV, PSV) </li></ul><ul><li>影響 Vt : △ P, Ti, TC (R, C), continuous flow rate (initial flow ->P. waveform shape) </li></ul><ul><li>優點 : ↓A. overdistention, ↑distribution, constant P., ↑MAP. </li></ul><ul><li>缺點 :variability by volume </li></ul>
  9. 9. Controlled Mode (Pressure-Targeted Ventilation) Time (sec) Time Triggered, Pressure Limited, Time Cycled Ventilation Pressure Flow Volume (L/min) (cm H 2 O) (ml) Time- Cycled Set PC level
  10. 10. 比較 PCV vs VCV <ul><li>↑ Oxygenation(↑ MAP) </li></ul><ul><li>- PCV : PIP-PEEP*Ti / TCT+PEEP...…. 正方形 </li></ul><ul><li>- VC : ½(PIP-PEEP*Ti / TCT+PEEP)... 三角形 </li></ul><ul><li>↑ gas exchange </li></ul><ul><li>↓ PIP </li></ul><ul><li>容易 lung healing </li></ul>
  11. 11. Assisted ventilation <ul><li>-- Pt trigger ( PSV, VS, PAV) </li></ul><ul><li>-- Preset volume or pressure, no mandatory </li></ul><ul><li>breath </li></ul><ul><li>-- time interval 不一定相等 </li></ul>
  12. 12. Assisted Ventilation <ul><li>F5-20 </li></ul>
  13. 13. Assisted Mode (Volume-Targeted Ventilation) Time (sec) Flow (L/m) Pressure (cm H 2 O) Volume (mL) Preset V T Volume Cycling Patient triggered, Flow limited, Volume cycled Ventilation
  14. 14. Assisted Mode (Pressure-Targeted Ventilation) Set PC level Time (sec) Patient Triggered, Pressure Limited, Time Cycled Ventilation Pressure Flow Volume (L/min) (cm H 2 O) (ml) Time-Cycled
  15. 15. Pressure Supported Ventilation (PSV) <ul><li>Pressure – targeted (or limit), Pt – trigger </li></ul><ul><li>Patient-initiated, patient-terminated </li></ul><ul><li>自動調整 maintains flow to reach preset PSV level keep this pressure until expiration </li></ul>
  16. 16. The end of inspiration(PSV) <ul><li>Decrease of peak flow to specific threshold </li></ul><ul><li>Above the fixed PSV level (1 to 3 cmH 2 O), sudden exp. effort from patient </li></ul><ul><li>A time end of the insp. </li></ul>
  17. 17. Flow criterion: % of inspiratory peak flow Pressure Pressure Support Flow ETS PEEP Peak Flow
  18. 18. Wider ETS range ETS can improve synchrony and change Ti of spontaneous breaths P F Too late switchover Proper switchover Too early switchover
  19. 19. PSV Time (sec) Flow (L/m) Pressure (cm H 2 O) Volume (mL) Patient Triggered, Flow Cycled, Pressure limited Mode Flow Cycling Set PS level
  20. 20. IMV / SIMV <ul><li>IMV </li></ul><ul><li>-- Time trigger , continuous (neonatal)or </li></ul><ul><li>demand flow </li></ul><ul><li>-- open IMV( 通大氣 ), close IMV( 儲存袋 ) </li></ul><ul><li>-- demand flow 外接 peep, 無法代償 ,trigger </li></ul><ul><li>困難 -> WOB↑ </li></ul><ul><li>SIMV </li></ul><ul><li>-- Pt or time trigger </li></ul><ul><li>-- Wait for the next insp. Effort ( time window ) </li></ul>
  21. 21. SIMV+PS (Volume-Targeted Ventilation) Set PS level PS Breath Flow-cycled Flow Pressure Volume (L/min) (cm H 2 O) (ml)
  22. 22. SIMV + PS (Pressure-Targeted Ventilation) PS Breath Set PS level Set PC level Time (sec) Time-Cycled Flow-Cycled Pressure Flow Volume (L/min) (cm H 2 O) (ml)
  23. 23. CPAP Time (sec) Flow (L/m) Pressure (cm H 2 O) Volume (mL) CPAP level
  24. 25. Inverse Ratio Ventilation (IRV) <ul><li>Techniques to increase I / E ratio </li></ul><ul><li>(1) VCIRV </li></ul><ul><li>-- slowing the flow rate -> flow cycle 結束 </li></ul><ul><li>-- use a inspiratory pause -> time cycle 結束 </li></ul><ul><li>(2) PCIRV </li></ul><ul><li>-- increase Ti -> time cycle 結束 </li></ul>
  25. 26. Improving PaO 2 with IRV <ul><li>Higher mean Paw </li></ul><ul><li>By the short Te ->end exp. P.↑ (intrinsic P.) </li></ul><ul><li>Improved distribution due to low mean insp. flow </li></ul><ul><li>Physiologic effect </li></ul><ul><li>-- ↓intrapulmonary shunt, improved V/Q </li></ul><ul><li>matching, ↓dead space ventilation </li></ul>
  26. 27. PCIRV <ul><li>Selection I / E ratio in a PEEP- like effect </li></ul><ul><li>Trap gas and ↑FRC and MAP </li></ul><ul><li>Monitor compliance, auto-PEEP, SvO 2 and C.O. </li></ul><ul><li>Will drop Vt as the auto-PEEP developed </li></ul><ul><li>(△P = PIP – EEP) </li></ul><ul><li>Auto-PEEP : measurement by flow waveform </li></ul>
  27. 28. Mandatory Minute Ventilation(MMV) <ul><li>Allows spontaneously breath but ensure MV </li></ul><ul><li>Ventilator support automatically adjusts, can be achieved by ↑PSV level or mandatory breaths ( veolar or CPUI ) </li></ul><ul><li>But Pt with low Vt and high RR will not initiate the ventilator support </li></ul><ul><li>Disadvantages – Alveolar ventilation not monitor, ↓clinician evaluation, MMV level not well defined </li></ul>
  28. 29. MMV <ul><li>T10-1 </li></ul>
  29. 30. Methods of delivery ( MMV ) <ul><li>Change in mechanical breaths </li></ul><ul><li>-- Bear 5, Erica, CPUI, Sechrist 2200B </li></ul><ul><li>Change in tidal volume </li></ul><ul><li>-- Veolar (change the PS level), Servo 300(VS) </li></ul><ul><li>Target V E , maintain adequate ventilation </li></ul><ul><li>During weaning – 80% on A/C, 90% on IMV </li></ul><ul><li>Set lower V E -> if Pt is alkalosis or hypocarbic (PaCO2↓) </li></ul>
  30. 31. Servo–controlled Pressure Ventilation <ul><li>A) Pressure augmentation -> real breath by breath </li></ul><ul><li>*P aug – Bear 1000 </li></ul><ul><li>*VAPS – Bird 8400sti </li></ul><ul><li>B) Closed-loop pressure ventilation -> next breath </li></ul><ul><li>*PRVC and VS – Servo 300 </li></ul><ul><li>*Auto - flow – Drager (Evita ) </li></ul><ul><li>*APV – Galileo </li></ul><ul><li>C) PAV (proportional assisted ventilation) , ASV (adaptic support ventilation) , ATC (automatic tube compensation) </li></ul>
  31. 32. Initial setting for Pressure Augmentation <ul><li>P aug only work with VV , target volume, an upper pressure limit (Bear 1000, 8400sti ) </li></ul><ul><li>Set P. = P plateau – PEEP </li></ul><ul><li>Set appropriate flow rate : </li></ul><ul><li>-- >30% for peak flow for a PS breath </li></ul><ul><li>-- high enough Ti does not longer than Te </li></ul><ul><li>-- lower than the actual peak flow -> Paw↑ </li></ul><ul><li>-- Select rectangular flow wave form ( ) </li></ul><ul><li>Weaning: </li></ul><ul><li>-- C L ↑ -> Vt ↑ => reduce the P. and adjust flow rate </li></ul>
  32. 33. Peak flow100Lpm pressure 25cmH2O volume set 0.8 L Dement peak flow 80Lpm set flow 40Lpm sustained until volume set 0.8 L Insufficient pressure level flow setting may too low T I is increased acheved Vt PS breath with high flow demand(strong active insp.) volume delivry before the flow decreases (flow drop 30% of peak flow into expiratory) No p’t effort the breath is time set flow 40Lpm(rectangular waveform) to deliverde Vt 0.8L P’t trigger No P’t trigger P’t trigger P’t trigger pressure spike
  33. 34. Closed – loop Pressure Ventilation <ul><li>Insp. Pressure is regulated , calculation of previous breath, in next breath 校正 </li></ul><ul><li>Decelerating flow of PCV with volume guarantee ( ) </li></ul><ul><li>PRVC - VS (Servo 300 ), Auto flow (Drager ), APV(Galileo) </li></ul>
  34. 35. PRVC vs. VS <ul><li>Volume target ventilation, pressure regulator </li></ul><ul><li>PRVC – Pt or time trigger, time cycle </li></ul><ul><li>VS – Pt trigger, flow cycle (5% of peak flow in Servo </li></ul><ul><li>300) </li></ul><ul><li>4 test breath </li></ul><ul><li>-- First one 5 (300c) or 10 (300a) cmH 2 O </li></ul><ul><li>-- The next 3 breaths will deliver 75% of the set Vt </li></ul><ul><li>-- Calculates compliance for the previous breath and adjust </li></ul><ul><li>insp. P. level ( <3 cmH 2 O ) on the next breath </li></ul>
  35. 39. Auto - flow <ul><li>Volume ventilation 之下 , 使 MV 自動調節 Insp. flow( depended on lung C, R )to change pressure, flow wave form-> </li></ul><ul><li>與 PRVC 不同點 : </li></ul><ul><ul><li>allow Pt in any phases for spontaneous </li></ul></ul><ul><li>breath </li></ul><ul><ul><li>包括 Bi-level V., IPPV, SIMV, MMV </li></ul></ul>
  36. 40. AutoFlow - In Action <ul><li>Set desired - Freq, T insp ,V T and PEEP </li></ul><ul><li>Set Upper Paw alarm( -5cmH 2 O ) </li></ul><ul><li>Set Upper Insp. V T alarm </li></ul><ul><li>Insp. Pressure will automatically adjust ( +3cmH 2 O )to equal set V T </li></ul>
  37. 41. Adaptive Pressure Ventilation (APV) <ul><li>The inspiratory pressure is adjusted within this range: (PEEP + 5cmH 2 O) to (high pressure alarm limit -10cmH 2 O) </li></ul><ul><li>If monitored TV is higher or lower than the TV(target).the insp pressure is gradually adjusted by up to 2cmH 2 O at per breath </li></ul>
  38. 42. Adaptive Pressure Ventilation (APV) VT Flow Pressure High Pressure limit -10cmH 2 O PEEP+5cmH 2 O +2cmH 2 O/breath
  39. 43. Proportional assisted ventilation ( PAV ) <ul><li>Pressure, flow and volume delivery are proportional to Pt spontaneous effort (Evita-PPS) </li></ul><ul><li>Pressure produces by the ventilator depends on </li></ul><ul><li>- - insp. flow and volume demanded by Pt effort ( 不需 setting) </li></ul><ul><li>-- only set amplification ( work load 的 ? % ) of ventilator </li></ul><ul><li>response to Pt effort </li></ul><ul><li>Disadvantages : </li></ul><ul><ul><li>only provide for assisted ventilation </li></ul></ul><ul><ul><li>cannot compensate for system leaks </li></ul></ul><ul><ul><li>resistance and compliance measured aren’t real time. </li></ul></ul>
  40. 44. Proportional Pressure Support PPS Airway pressure Resistance Compliance Breathing muscles R C P mus P aw P aw P mus The Equation of Motion P P C V R V aw mus      1 .
  41. 45. Proportional Pressure Support PPS <ul><li>If R and C of the patient are known, deviations from normal values can be targeted and appropriately compensated </li></ul><ul><li>During PPS, the patient should feel as if his lung mechanics are healthy </li></ul>
  42. 46. Automatic tube compensation ( ATC ) <ul><li>The flow in a difference in pressure between the two ends of the tube(E-T) </li></ul><ul><li>Compensates for the flow depend P. drop across the tracheal tube ( a function, not a mode ) </li></ul><ul><li>The narrower the tube ’ s diameter -> WOB ↑ </li></ul><ul><li>The length of the tube -> no significant on R tube </li></ul><ul><li>Setting – the size of tube </li></ul><ul><li>– amount of compensation </li></ul><ul><li>( 100% or partially ) </li></ul>
  43. 47. What is Tube Compensation? <ul><li>Not a mode , but a spontaneous breath type </li></ul><ul><li>Accurately overcomes the imposed inspiratory WOB through an artificial airway </li></ul><ul><li>Hybrid of PS (but more efficient at overcoming tube resistance) </li></ul><ul><li>Controls the patients carinal pressure to a constant preset PEEP value during inspiration </li></ul>
  44. 48. <ul><li>TC adds appropriate pressure to keep carina pressure at preset PEEP </li></ul>Tube Compensation - What the Carina Sees Higher Circuit Pressure No Decreased Carina Pressure Paw
  45. 49. PS Limitations For ET-Tube Compensation <ul><li>PS may under-support the WOB early in the inspiratory phase when flows are high </li></ul><ul><li>As patients wake, sleep, become agitated etc, PS is unable to compensate for variable demands </li></ul>10 PCIRC cmH 2 O INSP EXP 7.5 5 2.5 0 -5 -10 80 60 40 20 0 20 -80 40 60 0 4 8 12s 2 6 10 Higher Flow Insufficient Support L min V .
  46. 50. On Evita, in Action Green curve shows the calculated tracheal pressure in combination with increased airway pressure
  47. 52. Then What Is APRV? <ul><li>APRV is similar but utilizes a very short expiratory time for Pressure Release </li></ul><ul><ul><li>this short time at low pressure allows for ventilation </li></ul></ul><ul><li>APRV always implies an inverse I:E ratio </li></ul><ul><li>All spontaneous breathing is done at upper pressure level </li></ul>Spontaneous Breaths P T “ Release”
  48. 53. Airway pressure relieve ventilation APRV <ul><li>Two level of CPAP , applied for set periods time, allows spontaneous breathing to occur at both level </li></ul><ul><li>Set P high and P low and time spent at each level ( T high , T low ) </li></ul><ul><li>If P ’ t isn ’ t spontaneous , PCIRV and APRV 是不能辨別 </li></ul><ul><li>Is a CPAP system, allow augmentation of alveolar ventilation 經由 短暫 interrupting CPAP(relieve P. ) </li></ul><ul><li>Gas movement -> by decreasing Paw below </li></ul>
  49. 55. APRV <ul><li>傳統 pressure – limited IRV vs. APRV 之間關係 : </li></ul><ul><li>-- CPPV vs. IMV </li></ul><ul><li>Advantages : </li></ul><ul><li>1) Low peak Paw 2) Low intrathoracic P. 3) ↑ V/Q matching </li></ul><ul><li>Disadvantages : </li></ul><ul><li>1) ↓ transpulmonary P. ( 排除 CO 2 會有問題 ) </li></ul><ul><li>2) 沒有 spontaneous breath 時為 PCIRV </li></ul><ul><li>3) Effect of airway and circuit resistance on ventilation </li></ul><ul><li>4) Interference with spontaneous ventilation </li></ul>
  50. 56. Pressure Oriented Ventilation <ul><li>Spontaneous breathing on elevated pressure level with short pressure releases for improved CO2 eliminationsimple to adjust T high , T low , P high , P low </li></ul><ul><li>FiO2 and Ramp setting are still present </li></ul><ul><li>Apnea ventilation with adjustable alarm time T apnea </li></ul>APRV (optional) 14:39 add. settings Other Modees CPAP ASB MMV ILV 0 20 40 60 80 P aw -10 Other Ventilation --- --- IPPV Assist E ** *** 48 5 4.4 0.9 mbar P hoch P tief T hoch T tief mbar s s APRV Mode
  51. 57. Purpose of APRV <ul><li>ALI : ↓ FRC-> elastic WOB↑-> arterial hypoxemia </li></ul><ul><li>not ventilatory failure </li></ul><ul><li>Restoration of FRC to reverse hypoxemia before ventilatory failure occur </li></ul><ul><li>Indication : </li></ul><ul><li>* ↓ C lung with oxygenation failure ex : ARDS </li></ul><ul><li>* Ventilation failure may be 不適用 ( auto-PEEP, PaCO2 ↑ ) </li></ul>
  52. 58. Clinical use of APRV <ul><li>Adjustment of CPAP (P high) result in pul. Gas exchange and lung mechanics, by monitor of </li></ul><ul><li>-- PaO 2 , SpO 2 , PvO 2 , SvO 2 or BP and HR </li></ul><ul><li>After P-high, relieve Paw to P-low ( △ P ) , measure Vt , 如必要 ↑ P-high level or ↓ P-low </li></ul><ul><li>If frequency release ↑, 則 release time (T low ) 應逐漸 ↓ , 避免因 air trapping ↓-> Vt ↓ </li></ul><ul><li>Volume change depends on TC (C*R) </li></ul><ul><li>-- C ↓ -> release time ↓ ( <1.5sec) </li></ul><ul><li>-- Airway obstruction -> release time ↑ </li></ul>
  53. 59. Guidelines for Adjusting APRV - Timing Variables <ul><li>Set frequency that results in acceptable alveolar ventilation </li></ul><ul><ul><li>adjusted to maintain desired levels of PaCO 2 / pH </li></ul></ul><ul><ul><li>usual starting rate 6 - 10 b/min </li></ul></ul><ul><li>Release time 1- 2 seconds for adults (1 - 1.5 more common) </li></ul><ul><ul><li>often set to achieve a slight amount of auto-PEEP </li></ul></ul>
  54. 60. Guidelines for Adjusting APRV - Pressure Variables <ul><li>Upper PEEP level 10-30cmH 2 O determined by compliance , adjusted to achieve desired MAP and oxygenation </li></ul><ul><li>Lower PEEP level 3-5 cmH 2 O adjusted to affect FRC , MAP , and thus oxygenation </li></ul><ul><li>Oxygenation can be affected by increasing MAP through: </li></ul><ul><ul><li>increasing PEEP L </li></ul></ul><ul><ul><li>increasing PEEP H if less than 30 - 35 cmH 2 0 </li></ul></ul><ul><ul><li>lengthening T H if changes to either set frequency or T L is acceptable </li></ul></ul>
  55. 61. Which patients may be poor candidates for APRV <ul><li>Patients with increased airway resistance </li></ul><ul><li>Who are unable to empty their lungs in 2 seconds </li></ul><ul><li>Asthma and COPD patients </li></ul><ul><li>Examining expiratory flow pattern to determine increased resistance can be a reliable indicator </li></ul>
  56. 62. Bi–phasic Positive Airway Pressure <ul><li>Use the same principle as APRV </li></ul><ul><li>Pressure target with freedom of spontaneous breath on two level </li></ul><ul><li>Synchronization of spontaneous and mechanical ventilation (trigger window) with BiPAP </li></ul>
  57. 63. What is BiLevel Ventilation? <ul><li>Cycling between the two pressure levels can be synchronized to patient breathing </li></ul><ul><ul><li>BiLevel timing settings or triggered by patient effort </li></ul></ul><ul><li>The two pressure levels are called PEEP H and PEEP L </li></ul><ul><li>The two timing levels are T H and T L </li></ul>P T Synchronized Transitions PEEP HIGH PEEP LOW T LOW T HIGH Synchronized Transitions
  58. 64. What is BiLevel Ventilation? <ul><li>At either pressure level the patient can breathe spontaneously </li></ul><ul><ul><li>spontaneous breaths may be supported by PS </li></ul></ul><ul><ul><li>if PS is set higher than PEEP H , PS supports spontaneous breath at upper pressure </li></ul></ul>T PEEP High + PS P PEEP L PEEP H Pressure Support
  59. 65. Depiction of DuoPAP Ventilation Spontaneous Breaths Synchronized Transitions Clock Transition P HIGH + PS P LOW + Psupport Spontaneous Breaths P T P HIGH P LOW /PEEP/CPAP P LOW P HIGH P T
  60. 66. BIPAP* allows Spontaneous Breathing during the Mandatory Stroke <ul><li>Reduction of the invasivness of Ventilation </li></ul><ul><li>Reduction of Sedation </li></ul><ul><li>One Ventilation Mode from Intubation to Weaning </li></ul><ul><li>More comfortable for the Patient </li></ul><ul><li>Fewer Alarms (easier handling) </li></ul>PCV Spontaneous Breathing BIPAP
  61. 67. BIPAP and the Synchronisation of Spontaneous Breathing <ul><li>The set BIPAP phase synchronises with Spontaneous Breath </li></ul><ul><li>Smooth synchronisation of the mandatory strokes with appropriate time window </li></ul><ul><li>Flow-trigger in Inspiration and Expiration </li></ul>P t Exp. Trigger Insp. Trigger Trig. Window Trig. Window
  62. 68. 3 New BiLevel Settings <ul><li>Timing button </li></ul><ul><li>Upper pressure level button - PEEP H </li></ul><ul><li>Lower pressure level button - PEEP L </li></ul>f 1 min 16 0 5 V-TRIG . T H S 1.75 1.75 1:1.14 2.0 P % 50 O 2 % 50 _ P CIRC cm H 2 O 25 PS P SUPP H 2 O 15 V SENS L min 5 BiLEVEL PC 10 % PEEP H 20 cm H 2 O PEEP L 5.0 H 2 O cm E SENS 3.75 cm
  63. 69. T HIGH Setting <ul><li>T H can then be directly adjusted </li></ul><ul><li>Range 0.2 to 30 seconds </li></ul>1.75 f 1 min 16 0 5 V-TRIG . 3.75 T H S 1.75 1:1.14 2.0 P % 50 H 2 O PEEP H 20 cm O 2 % 50 _ P CIRC cm H 2 O 25 PS P SUPP H 2 O 15 V SENS L min 5 BiLEVEL PC 10 % PEEP L 5.0 cm H 2 O E SENS 1.75 cm
  64. 70. T HIGH : T LOW Setting <ul><li>When I:E ratio is locked, T H : T L is is the displayed button and can be adjusted directly </li></ul><ul><li>Range 1:299 to 149:1 </li></ul>f 1 min 16 0 5 V-TRIG . 3.75 1.75 1:1.14 2.0 P % 50 H 2 O PEEP H 20 cm O 2 % 50 _ P CIRC cm H 2 O 25 PS P SUPP H 2 O 15 V SENS L min 5 BiLEVEL PC 10 % PEEP L 5.0 cm H 2 O T H : T L 1: 1.14 E SENS cm
  65. 71. T Low Setting <ul><li>When T L is locked on the breath timing bar, T L is present on the timing button and can be set directly </li></ul><ul><li>Range .2 seconds or higher </li></ul>f 1 min 16 0 5 V-TRIG . 3.75 1.75 1:1.14 P % 50 H 2 O PEEP H 20 cm O 2 % 50 _ P CIRC cm H 2 O 25 PS P SUPP H 2 O 15 cm V SENS L min 5 BiLEVEL PC 10 % PEEP L 5.0 cm H 2 O E SENS T L S 2.0 2.0
  66. 72. APRV versus BIPAP different philosophies BIPAP P insp CPAP Ventilation P high P low APRV
  67. 73. Adaptic Support Ventilation (ASV ) <ul><li>Machine - and/or patient -triggered. </li></ul><ul><li>Gas delivery is pressure-controlled for both mandatory and spontaneous breaths . Pressure levels are identical. </li></ul><ul><li>Mandatory breaths are time-cycled if they were NOT triggered by the patient; spontaneous breaths are flow-cycled. </li></ul>
  68. 74. ASV Pinsp PEEP No patient activity: * Machine-triggered + Time-cycled Patient is active: * Patient-triggered + Flow-cycled Flow I Flow E * * + +
  69. 75. Optimal breath pattern <ul><ul><li>1+2a*RCexp*(MV-V‘D)/VD -1 </li></ul></ul><ul><ul><li>f-target = </li></ul></ul><ul><ul><li>a*RCexp </li></ul></ul>
  70. 76. Lung-protective rules (boundary conditions) D A C B 5 test breaths 10*Vd 5 b/min 20/RCexp 2*Vd 0 500 1000 1500 2000 0 20 40 60 f (b/min) Vt (ml)
  71. 77. Optimal breath pattern: Lung protective strategy Avoid: a: apnea b :volume/barotrauma c: AutoPEEP d: excessive VD ventilationon /tachypnea 0 500 1'000 1'500 2'000 0 10 20 30 40 Frequency in breaths per minute Vt in ml a b c d
  72. 78. 結語 <ul><li>呼吸器是用來活命 (supportive) 而不是用來治病 (curative or therapeutic) 的─ </li></ul><ul><ul><li>支持衰竭的呼吸系統 (failing respiratory system) ,直到病人的呼吸功能因治療或自然回復功能 </li></ul></ul><ul><ul><li>避免呼吸器引起之「醫源性肺損傷」 (iatrogenic lung injury) 與其他併發症 </li></ul></ul><ul><li>不要用呼吸器來延長死亡過程─ </li></ul><ul><ul><li>癌症末期病人 </li></ul></ul><ul><ul><li>末期之慢性呼吸衰竭 </li></ul></ul><ul><ul><li>無復原希望之疾病 </li></ul></ul>
  73. 79. Thanks for your attention

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